I made a concept based off of Kirby methods to make a mp map. It was ported to PC; the server ran a copy that had scripts, the clients ran a copy without scripts. This only works in PC (not custom edition) as the custom edition does a file check to make sure they match. By separating the scripts and putting them on host there are no duplicate bots; no need to use fancy spawning areas or anything to keep out dummy AI.

It works, but its extremely laggy as though youre on 56k. Also, mine was a MP slayer map. Not a true SP map

The reason, Bat-whatever, is because the engine doesnt support it. The only way to simulate it is to do workarounds and manipulate the game's netcode. Halo 1 does not support AI over a network